class Mythread extends Thread{
    @Override
    public void run() {
        while(true){
            System.out.println("hello t");
            try{
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

public class demo1 {

    public static void main(String[] args) {
        Thread t = new Mythread();

        t.start();

        while(true){
            System.out.println("hello main!");
            try{
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}
